Really, the cable is the only significant thing we don’t have yet. There are other problems, too, of course, but once we have the material for the cable, everything else will quickly fall into place. And the great thing about the cable is that carbon nanofiber would be an incredibly useful material for many purposes, on Earth and in space. Even if nobody’s trying for a space elevator, they’ll still work on producing nanofiber for suspension bridges and skyscrapers (and fishing lines and golf clubs, of course).
At the moment, the only direct commercial values in space flight are satellites, which can provide a variety of commercial (and non-commercial) benefits. Zero-g crystallography gets a lot of hype, but for now, it’s mostly just hype. But if we really got an industrial presence up and running in space, there’s a lot we could do. A space elevator or other cheap launch system would help a lot, of course, but even without cheap launches, I could envision asteroid mining, for instance, being profitable in the long term. Once the infrastructure is in place, you could keep it all in orbit, and just bring an asteroid on a controlled re-entry every so often, for a cheap supply of iron, nickel, and other metals. Remember, no matter how expensive it is to get things up there, it’s almost free to get them down.
Which raises another point: There was a time when we might have hoped commercial exploitation in space could be piggybacked on military space travel – who controls the sky controls the surface, and if the military program included manned orbital platforms, they might need a lot of independent contractors for entertainment, just to start with . . .
But the Cold War is over, and our perceived enemies of the moment are not likely to have any space-travel capacity in our lifetimes.
Plus there is always the null-G sex industry. Blind folded pin the tail on the, er…well, whatever you want to pin the tail on I guess. Could be big (cough cough)!
I recall a filksong – “A Reconsideration of Anatomical Docking Maneuvers in a Zero-Gravity Environment,” by Diana Gallagher – about the [ahem] technical challenges. Solutions suggested included:
Together tethers would prevent a random wandering
Magnetic harnesses incorporating alternating poles . . .
Can’t find the complete lyrics online, but I did find the lyrics to this one.
You’re kidding, surely? Whaddya gonna do, climb up the rope?
We’re not talking about a 62-mile climb; it’s a 62,000 mile climb. You do need some sort of engine to get you up there, and unless you want it to be a remarkably long trip, it has to be reasonably fast.
It’s simply a project of staggering potential cost that would require the commitment of a fairly noticeable fraction of the world’s resources. Christ, the space station alone that holds the other end of the tether could cost a trillion dollars. The insanity of a $40 billion price tag can be quickly illustrated by pointing out that the International Space Station, which is about one hundredth as technologically challenging and complicated to build, cost at least $30 billion.
I was thinking of al-Qaeda, the Taliban, etc. – guys who couldn’t tell a spaceship from a portrait of the Prophet. As for Iran, even if they ever do develop a nuke, do they have the capacity to get it out of the atmosphere?
Arthur C Clarke wrote a SF novel around a space elevator.
It might be there that I picked up the idea that a long cable actually pulls itself up, something to do with negative centripetal force. There is also the way a yoyo works.
If we had the fibre technology, then the rest of the task could be comparatively low tech - a sort of bootstrap operation.
Lotsa people have, by now. Clarke’s Fountains of Paradise came out back in 1982 or so, at almost exactly the same time as Stanley Schmidt’s The Web Between the Worlds, to which Clarke wrote the introduction. He pointed out the incredible similarities, which he attributed mainly to the fact that they were both extrapolating from the same background. In Clarke’s story the fibers are defect-free carbon. In Schmidt, defect-free silicon. Both novels have “climbers” for the space elevators named “Spider”
On the same Wiki page, they compare pressure ranges of Outer Space to various “grades” of vacuum. Outer space ranges from merely “High” to “Extremely High” Vacuum. “High” vacuum is easily achieved in an undergraduate laboratory. If you keep things clean, you can approach Ultra High Vacuum in an undergraduate setting.
I worked with Ultra-High Vacuum systems for a time (better than High vacuum, not as good as Extremely High vacuum). What you want from a vacuum system is a controlled, extremely clean environment. Just “opening up the window” on a spacecraft will NOT do. Spacecraft outgass all kinds of miscellany. If you want an atomically clean surface you don’t want crap outgassing on it. At 10^-6 torr (middle of the “high vacuum” range), a single layer of contaminants forms on a surface in about a second. At 10^-9 torr (UHV), that would be about 1,000 seconds = 17 minutes. Doesn’t give you a lot of time for surface processing or analysis.
UHV systems are not terribly cheap, since they require stainless steel construction, high-quality welds, multiple pumps, and scrupulous cleaning. But they are much cheaper than anything in orbit.
That’s the big hang-up with space industries, IMNSHO. It is prohibitively expensive to put stuff in space. Bob Park, skeptic extrordinaire, said that if we filled the space shuttle with coal dust at launch, and - just by it going into orbit - it returned full of diamonds, that would still not pay for the cost of the shuttle mission. I have no cite, and I have not run the numbers myself, so he could be wrong. But I am confident he’s closer to being right than space advocates would like.
Typo – Having worked with vacuum systems myself, I gotta say that the advantages of a huge, almost maintenance-free vacuum system speak for themselves. I’d no more just stick my vacuum thing outside an outgassing spaceship that put it near a plastic window in a vacuum on earth. But in a low-outgassing box in space I’d have a low-vacuum area that wouldn’t require a series of pump or cold traps. Heck, put it on the dark side of something and you have a built-in cold trap. If you already have you stuff in space, having mined it there, you have a good incentive for using space as your vacuum.
The cutting edge of Space Elevator optimism is here in Washington State. LiftPort Group is aiming at having the thing done by 2018 for roughly 6-10 billion dollars US. I’m wishing them well.
They say their progress in developing the tech to form the ribbon is actually a little ahead of the schedule they expected to achieve, but the power-beaming tech they’ll need to power the lifters is a bit behind.
A 62,000 mile long power cable? You’d lose a massive amount of power along the way; that’s orders of magnitude longer than any power line used today. How’re you going to reduce power loss?
